One of flat panel displays (FPDs) realizing a thin and large screen is a liquid crystal display (LCD). For example, low-temperature poly-Si (LTPS), which may be produced at low temperature, is used for a thin film transistor (TFT) of the liquid crystal display.
A laser anneal process is generally used to form a polycrystal silicon (p-Si) thin film in a LTPS production line. Unlike amorphous silicon (a-Si), the polycrystal silicon has a partially crystalline structure and is produced as follows. Plasma-enhanced chemical vapor deposition (PECVD) is used to form an a-Si thin film (approximately 50 nm to 100 nm) on a glass substrate. The glass substrate is scanned on a stage with a laser beam to melt and recrystallize the a-Si film. A laser anneal apparatus for performing the laser anneal process as described above is publicly known (see, for example, Patent Literature 1).
A projection display device uses a laser light as a light source to display an image on a screen. Unlike a cathode ray tube (CRT) display and a plasma display panel (PDP), the projection display device is a non-emission display device and includes a light valve for adjusting a light amount based on an image signal, an illumination optical system for illuminating the light valve with illumination light from the light source, and a projection optical system for enlargedly projecting a small image formed by the light valve to a large screen.